Beispiel #1
0
/*
	Attempts to load a Graph at the given dir, or creates a new one if no graph repo is found.
	If a new graph is fabricated, it will be initialized by:
	 - creating a new git repo,
	 - making a blank root commit,
	 - and tagging it with a branch name that declares it to be a graph repo.

	Note if your cwd is already in a git repo, the new graph will not be commited, nor will it be made a submodule.
	You're free to make it a submodule yourself, but git quite wants you to have a remote url before it accepts your submodule.
*/
func NewGraph(dir string) *Graph {
	g := newGraph(dir)
	if g.isHrootGraphRepo() {
		// if we can just be a load, do it
		return g
	} else if g.isRepoRoot() {
		// if this is a repo root, but didn't look like a real graph...
		util.ExitGently("Attempted to make a hroot graph at ", g.dir, ", but there is already a git repo there and it does not appear to belong to hroot.")
	} // else carry on, make it!

	// we'll make exactly one new dir if the path doesn't exist yet.  more is probably argument error and we abort.
	// this is actually implemented via MkdirAll here (because Mkdir errors on existing, and I can't be arsed) and letting the SaneDir check earlier blow up if we're way out.
	err := os.MkdirAll(g.dir, 0755)
	if err != nil {
		panic(err)
	}

	// git init
	g.cmd("init")("--bare")()

	g.withTempTree(func(cmd Command) {
		// set up basic repo to identify as graph repo
		cmd("commit", "--allow-empty", "-mhroot")()
		cmd("checkout", "-b", hroot_ref_prefix+"init")()

		// discard master branch.  a hroot graph has no real use for it.
		cmd("branch", "-D", "master")()
	})

	// should be good to go
	return g
}
Beispiel #2
0
func (g *Graph) Load(lineage string, gr GraphLoadRequest) (hash string) {
	lineage, _ = SplitImageName(lineage) //Handle tags

	//Check if the image is in the graph so we can generate a relatively friendly error message
	if !g.HasBranch(hroot_image_ref_prefix + lineage) { //HALP
		util.ExitGently("Image branch name", lineage, "not found in graph.")
	}

	g.withTempTree(func(cmd Command) {
		// checkout lineage.
		// "-f" because otherwise if git thinks we already had this branch checked out, this working tree is just chock full of deletes.
		g.cmd("checkout", "-f", git_branch_ref_prefix+hroot_image_ref_prefix+lineage)()

		// the gr consumes this filesystem and shoves it at whoever it deals with; we're actually hands free after handing over a dir.
		gr.receive(".")

		hash = "" //FIXME
	})
	return
}